A growing number in Congress is looking to limit US authority to kill suspected terrorists, including American citizens. The Democratic-led outcry at the Obama administration's use of deadly drones was emboldened by the revelation in a newly surfaced Justice Department

memo that shows drones can strike against a wider range of threats, with less evidence, than previously believed.

The drone program, which has been used from Pakistan across the Middle East and into North Africa to find and kill an unknown number of suspected terrorists, is expected to be a top topic of debate when the Senate Intelligence Committee grills John Brennan, the White House's pick for CIA chief, at a hearing Thursday. (AP)